Gas and liquid fuel burner assembly



2 Sheets-Sheet 1 R. D. REED ETAL GAS AND LIQUID FUEL BURNER ASSEMBLY Aug. 12, 1958 Filed Dec. 27. 1955 INVENTORS ROBE/i T 0. RE E 0 ATTORNEY JOHN S. Z/NK JR. ROBERT [P DUNCAN 2, 1958. R. D. REED ET AL 2,847,063

GAS AND LIQUID FUEL BURNER ASSEMBLY Filed Dec. 27, 1955 2 Sheets-Sheet 2 INVENTORS ROBERT 0. RE E 0 JOHN 3. Z INK JR.

ROBE I77 I? DUNCAN I BY I if. P M ATTORNEY United States Patent f GAS AND LIQUID FUEL BURNER ASSEMBLY Robert D. Reed, John S. Zink, Jr., and Robert P. Duncan, Tulsa, Okla., assignors to John Zink Company, Tulsa, Okla., a corporation of Delaware Application December 27, 1955, Serial No. 555,468

1 (Ilaim. (Cl. 158- 106) The present invention relate-s to a burner assembly wherein a plurality of gas burners are arranged in an annular outline about a liquid fuel burner with the gas burners so constructed and arranged that the shape and length of the flame may be controlled.

The prior art includes fuel burners wherein oil is burned in combination with one or more burners supplied with a gaseous medium. An object of the present invention is to so mount the gas burners that the burner heads may be adjusted whereby the flame pattern of the burner assembly may be varied to provide that the burning fuel discharged by the gas burners meet a common zone at the center-of the assembly to provide a flame pattern having an elongated shape and the burner heads may be adjusted so that the flame developed by each gas burner is in a direction generally tangentially of the assembly.

Another object of the invention is to provide a mounting of the burner heads supplied with gaseous fuel so that the shape of the flame may be altered to have patterns between the elongated shaped flame and the flame pattern which is developed when the burner heads discharge the gaseous fuel in directions generally tangentially of the assembly.

. A further object of the invention is to provide means for controlling the admission of air to the burner assembly including means for adjusting the volume of the secondary air admitted to the presence of the oil burner and means for controlling the volume of air admitted to the presence ofthe gas burners.

Other objects and featuresof the invention will become apparent to those skilled in the art as the present disclosure proceeds and upon consideration of the accompanying drawings and the following detailed description wherein several embodiments of the invention are disclosed.

In the drawings: r j

Fig. 1 is an axial sectional view of a burner assembly exhibiting the invention.

Fig. 2 is a sectional view taken on the line 22 of Fig. l.

Fig. 3 is a similar view showing the closed position of the shutter mechanism for controllingthe volume of air admitted to the presence of the gas burners.

Fig. 4 is: an enlarged sectional view illustrating the manner in'which one of the mixing tubes for one gas burner is mounted for adjustment. 7

.FigJS is a diagrammatic View illustrating one adjusted position of the gas burners and Fig. 6 is a similar view illustrating another position of the gas burner tips.

Fig. 7 is an enlarged sectional view illustrating a modified mechanism for controlling the volume of secondary air admitted to the presence of the central burneri Fig. 8 is a plan..view of. a vane supporting plate employed in the air control mechanism taken on the line 8% of Fig. 7. a

ice

Fig. 9 is an end view of a slotted disc serving as an air door for the arrangement shown in Fig. 7.

Fig. 10 is a diagrammatic view showing the approximate shape of the resulting flame when the gas burner heads are directed radially inward.

The invention is directed to a burner assembly wherein a plurality of gas burners are arranged in an annular outline about a central burner which may be supplied with a liquid fuel. The tips of the gas burners may be adjusted with reference to the axis of the assembly so that the gaseous fuel upon discharge from the gas burners will form a flame pattern of an elongated character-or a flame pattern wherein the fuel issuing from the gas burners moves generally tangentially of the assembly to provide a flame of relatively large diameter which is relatively short measured axially downstream from the burner assembly.

Referring to the drawings a furnace wall is shown at 10 provided with a relatively large circular opening 11. A tile is provided in the opening 11 formed of refractory material and in the embodiment illustrated this device may take the form of two rings 12 and 14 formed of suitable ceramic materials to provide a refractory member having a convex shaped inner profile with a relatively large central opening 16 therethrough. The refractory structure may be maintained in position within the opening 11 in any suitable manner and the outer surface of the furnace wall may be covered with sheet metal 17.

The organization includes a smaller ceramic member. 18 formed of refractory material and having a central opening 19 therethrough which is of progressively larger diameter in proceeding towards the interior of the furnace. The refractory member 18 may be covered with sheet metal 21. It will be observed that the outer diameter of the refractory member 18 is of less diameter than the opening 16 in the larger refractory member.

A cup-shaped frame member 22 is secured to the furnace wall structure by means of cap screws 23. The frame member 22 includes a closed end portion 24 and the sidewall 25 thereof is provided with a plurality of windows or apertures 26. These openings may be of any desired shape but are preferably of rectangular outline. In the embodiment illustrated in the drawings four such windows are provided in the cylindrical wall 25. The cup-shaped frame 22 provides support for a central burner 27 having a hub portion 28. The oil burner 27 includes a tip 29 which is disposed to direct voil in atomized condition in a direction along the axis of the opening 19 in'the ceramic membe 18 and along the axis of the opening 16 in the larger ceramic member. A tube 31 is adapted to be connected to an oil supply for guiding oil into the oil burner. The oil burner structure is supported by a cup-shaped frame member 33 which -is secured to the end wall 24 of the frame member 22 by means of cap screws 34. r 1

The frustro-conical side wall 32 of the cup-shaped frame member 33 is provided with a plurality of aper tures 36. In one embodiment four such openings are provided and each is desirably of rectangular shape. A sleeve 37 embraces the side wall 32 of the cup-shaped frame member 33 and is adapted to rotate therearound. The sleeve 37 is provided with a plurality of openings 38 which are circumferentially displaced from each other corresponding to the circumferentially spacing of the apertures-36. In one rotated position the openings 38 are in registration with the apertures 36 and a maximum amount of air is admitted so as to pass over the tip of the central burner. Smaller quantities of air are ad mitted by rotation of the sleeve 37 to control the area of the openings and thus vary the volume of air'admitted to move into the presence of the burnertip 29;

The assembly includes a plurality of gas burners arranged in a circular outline about the periphery of the small refractory member 18. Any desired number of gas burner heads 41 may be so arranged and in the embodiment illustrated four of such burners are employed. Each gas burner may have a tip portion having flame retention characteristics as shown and described in the link 'Patent 2,462,704, dated February 22, 1949, although other types of .burner heads may be employed. Each burner 41 is mounted on a relatively short tubular member 42 having the axi thereof disposed at an angle with reference to the axis of the assembly. The pipe 42 of one burner is rigidly connected to a mixing tube 43 which is disposed in a position with its axis parallel to the axis of the burner assembly. The axis of the pipe 42 of each gas burner is arranged at angle of about twenty degrees with respect to the axis of the associated mixing tube 43. This angle may vary between ten and thirty degrees.

Each mixing tube 43 is connected to a mixing body 44 in such a manner that the mixing tube 43 may be rotated about its axis with respect to the mixing body 44. An annular manifold 46 is provided supplying gaseous fuel under pressure to all of the gas burners. The gaseous fuel is released through an orifice 47 into each mixing tube. 43 and primary air is induced to move into the mixing body 44 of each burner so that a mixture of .gas and air is supplied to each gas burner tip. Each mixing tube 43 is supported by means of a member 49 on the end wall 24 of the frame 22 in such a manner that each mixing tube 43 may rotate with reference to its member 49. A set screw 51 or the like is provided in each member for holding the mixing tube in a rotated and adjusted position. Such a mounting of the mixing tubes supports the members 44, the gas supply nipples 52 and the manifold 46 on the cup-shaped frame member 22.

A shutter or cylindrical shaped member 56 surrounds the sidewall 25 of the frame member 22. The member 56 is provided with a plurality of Windows or apertures 57 which are so spaced that they may be brought into registration with the apertures or windows 26 or rotated to completely close these windows as shown in Fig. 3. Such an assembly provides for an adjustment of the volume of air admitted to the exterior of the small ceramic member 18 for movement into the presence of the gas burners 41. The shutter 56 may be adjusted by handles 55.

In operation the burner heads 41 may occupy positions shown in Figs. 1 and so that the flames developed by the fuel discharged therefrom converge towards each other in proceeding upwardly so as to provide an elongated flame 60 as shown in Fig. 10. The mixing tubes 43 may be each rotated about its axis so that the burner heads 41 are disposed in positions as shown in Fig. 6. The resulting flame pattern is one in which the burning fuel developed forwardly of one head does not intermingle with that developed by an adjacent burner head and a pattern of flames is provided somewhat as depicted in Fig. 6. Accordingly a heating zone of relatively large diameter is provided and having a relatively short length measured downstream from the burners. The burner heads 41 may be fixed in any adjusted position between the extreme settings shown in Figs. 5 and 6 to provide still further flame patterns.

A modified mechanism is shown in Figs. 7 to 9 for controlling the volume and the direction of air admitted to the presence of the central burner 27. In this embodiment a vane plate 71 is mounted so as to lie along the lower surface of the closed end 24 of the cup-shaped frame member 22. This vane plate has a relatively large central opening 72 in registration with the central opening 19 in the small refractory member 18. A plurality of vanes 73 are carried by the vane plate 71 and these vanes are disposed in chord positions. In this embodiment the oil burner 27 is supported by a bracket having arms 76 with open areas therebetween supporting a boss 77. A set screw 78 threaded in the boss '77 provides for holding the oil burner in position. The arms 76 may be secured to the end wall 24 of the frame member 22 by means of cap screws 79. These cap screws extend through holes 80 in cars to hold the vane plate 71 in fixed association with the other parts.

The volume of air admitted to the presence of the oil burner is controlled by means of a disc shaped air door 81 which is mounted for sliding movement on the oil burner 27. The air door may be securedin any adjusted positions by means of a 'set screw 83 which is threaded in a boss 82 carried by the disc 81. The air door is provided with a plurality of slots 84 for receiving portions of the vanes 73. The air entering between the arms 76 is diverted circumferentially about the central burner by the vanes 73.

While the invention has been described with reference to specific structural features and with regard to one type of burner head it will be appreciated that changes may be made in the elements as well as the overall organization. Such modifications along with others may be made without departing from the spirit and scope.

of the invention as set forth in the appended claim.

What We claim and desire 'to secure by Letters Patent In a fuel burner assembly for firing into a ceramic lined opening in a furnace wall, a cup-shaped frame adapted to be secured to said wall, an end portion on said frame adapted to be spaced from said wall, an annular refractory member carried by said end portion having a smaller diameter than the cup-shaped frame, said end portion having an opening therethrough registering with the interior of the upstream end of said annular refractory member, a plurality of mixing tubes arranged in circumferentially spaced relationship around the exterior of said refractory member each extending substantially parallel to the axis of the refractory member, a pipe rigidly connected to the downstream end of each mixing tube and disposed at an angle with respect to the axis of the associated mixing tube, a burner head carried by the downstream end of each pipe having a discharge orifice aligned with the axis of the associated pipe, each of said mixing tubes extending through an opening in said end portion, a member surrounding each mixing tube carried by said end portion for supporting the mixing tubes with each mixing tube rotatable about its axis, a manifold including means associated therewith for supplying gaseous fuel into each mixing tube, means for supporting the manifold on all of the mixing tubes, said cup-shaped frame member having circumferentially spaced windows therein, an annular shutter surrounding said cup-shaped frame and said windows and supported for rotation thereon, said shutter having circumferentially spaced openings therethrough, and means for controlling the a volume of air admitted through said opening in said end portion for movement into the interior of said refractory 

